Improvement in hydronettes, hand-pumps, and syringes



w. l3; ROBINS. HydronettsyHand-Puhp s andsyri'ng'e. No. l54,343.'

Patented Aug. 25, 1874.

MQAQM y a n r 0 t t d y B UNITED STATE PATENT OFFICE.

WILLIAM B. nonnvs, or NO. 133 LAIJBROKE enovn, ASSIGNOR ro EDWARD HAYNES AND HENRY HAYNES, or 227 EDGEWARE ROAD, ENGLAND.

IMPROVEMENT IN HYDRON ETTES, HAN D PUMPS,AND SVRINGES.

Specification forming part of Letters Patent No. 154,343, dated August 25, 1874 application filed A June 6, 1874.

- by the following statement thereof-that is to say:

This invention has for its object improvements in pistons for hydronettes, hand-pumps, and syringes.

In order-that the piston in such instruments may be made to fit the barrel, so as to prevent any leakage during the forcing stroke, and

- yet work freely and with little friction, -I employ a leather disk, fixed upon the piston-rod, so as to act as a piston. It is cupped, so as to tend to expand against the sides of the barrel during the forcing stroke; but the complete expansion of the cupped disk isinsured by mechanical means. There is also mounted upon the piston-rod a sliding piston, which is packed with a fibrous packing, to fit the bar- -rel easily. This piston has an annular projection upon it, corresponding to the concavity of the cupped leather disk, and, at the commencement of the forcing stroke, this projection, is made to strike upon the leather disk, entering the hollow of the leather and expand ing-it against the sides of the barrel. Thus a blow tending to open and expand the cupped leather is given to it at each stroke, the piston-rod at the commencement of the forcing stroke carrying the cupped leather with it, but the sliding piston remaining stationary in the barrel for an instant, until the leather strikes against it, and then both move on together to the end of the stroke, separating again by a short space at the commencement of the return or suction stroke.

The annexed drawing shows an elevation, partly in section, of a piston-hydronette havin g these improvements applied to it.

a is the barrel. It is fixed at one end into a socket-piece, b, to which a flexible suctionpipe is attached. A valve-seat is ground within the piece b, which also contains the metallic ball-valve c. It is prevented from escaping by the pin b. The other end of the barrel a receives a screw-cap, d, which serves as a guide for the hollow piston-rod c. This pis-. ton-rod also serves as the passage by which the water passes to the delivery-nozzle f. g is a union-piece, screwed onto the piston-rod e, and onto which the nozzle f is in turn screwed. h is a tubular handle. The pistonrod passes through it, and it is retained in its place between the collar 6 upon the rod, and the union-piece g screwed onto the end. There is a valve-seat at the lower end of the hollow piston-rod e, and a spherical metallic valve, 'i, is retained within this part of the hollow rod 6 by the pin 0 The piston consists of several parts. 0 is a metal collar fixed on the piston-rod. It is of such a size that it does not come in contact with the sides of the barrel. It is concave on its face, and supports a cupped leather disk, is, which is of a size to fit closely the interior of the barrel. 1 is a metal piston, free to slide on the piston-rod, and l is a worsted packing, with which this piston is provided. m is a stop-nut to retain the piston 1 upon the rod. It has aleatherwasher, m, upon its face. The piston l is able to slide to and fro between the nut m and the cupped leather disk is. The suction mainly depends upon the worsted packing of the movable piston. This piston, at the commencement of the suction stroke, remains stationary, while the leather disk It recedes from it, and until the leather-covered face of the nut m comes against it, it then moves with the rod for the remainder of the stroke. In the forcing stroke the movable piston lstands still at the commencement of the stroke, and until the cupped leather disk is strikes it, and it is this blow which expands the leather and makes it fit the barrel perfectly water-tight. n is a rose, to be substituted, when desired, for the nozzle f.

In hydronettes of the construction which the-drawing represents, it is of great-iimportanoe'that thBiPiStOil should-not-aIlow-any water to accumulate over the piston, as other wise the water passing the piston would be driven out through the cap d, around the piston-rod, and would be a-serionsannoyanoe to the user offthe instrument. *Gompouud'pis tons of this construction are applicable to other forms of hand pumps, and also to syringes. a L

The syringe differs rose by which the water is drawn into and expelled from the harrel' take's the'plaee of thef socket-piece b.

l 4 I A a contact with the barreL. from "the 'hytlronette, mainly, in having a solid pistonrod, and the,

WILLIAM BU'R- T "ROBINS. Witnesses:

W.F.,W'AR 1-,-

WILMERTM A'RRJTS Both of N0. 17 Graceckm ch Street, London. 

